More particularly still, the present invention seeks to improve the lock described and shown in European patent application No. 83 400 367.5 filed Feb. 22nd, 1983, by the corporation Initial Sarl, and published under the No. 0 088 012.
Reference can usefully be made to said prior published European patent specification No. 0 088 012 for a full understanding of the present invention.
The cylinder lock described in said prior European application comprises:
a stator;
a rotor surrounded by said stator;
a latch associated with said rotor;
at least one locking member disposed between said rotor and said stator, said locking member being suitable for being displaced between a locking position in which it prevents rotation of said rotor relative to said stator, and a release position in which it allows such rotation;
a plurality of coaxial coding elements, each coding element having a notch in its periphery suitable for receiving said locking member in its release position, and also having drive member suitable for rotating each of said coding elements when one of the coding elements immediately adjacent thereto is itself rotated; and
a rotary element-decoding member suitable for rotating one of said elements and for enabling said notches to be brought into alignment.
In order to change the combination of the lock described in said European published patent application No. 0 088 012, it is necessary to open the lock and disassemble its various coding elements in order to modify the relative positions of the notches and the drive members of each element.
This kind of disassembly is tedious and difficult, and can only be performed by specialists who have full knowledge of the structure and the operation of the lock.
This constraint has limited the development of locks such as described in said European patent specification No. 0 088 012.